TW202145859A - Weight optimized stiffener and sealing structure for direct liquid cooled modules - Google Patents

Abstract

A weight optimized stiffener for use in a semiconductor device is disclosed herein. In one example, the stiffener is made of AlSiC for its weight and thermal properties. An O-ring provides sealing between a top surface of the stiffener and a component of the semiconductor device and adhesive provides sealing between a bottom surface of the stiffener and another component of the semiconductor device. The stiffener provides warpage control for a lidless package while enabling direct liquid cooling of a chip or substrate.

Description

Weight-optimized stiffeners and seals for direct liquid cooling modules

Complementary Metal Oxide Semiconductor ("CMOS") circuits are found in several types of electronic components including microprocessors, batteries, and digital camera image sensors. The main features of CMOS technology are low static power consumption and high noise immunity.

In addition to industry-standard chip packaging, the search for specialized silicon can lead to high-power heat sources in servers. This technology can also be applied to graphics processing units ("GPUs") and custom application-specific integrated circuits ("ASICs"). In addition, services such as imaging and artificial intelligence ("AI") will likely require high densities of massive computing resources, with many servers in close proximity to each other. Data centers around the world are being asked to simultaneously improve energy efficiency, consolidate operations and reduce costs. To accommodate these high-performance and high-density servers, data center operators must address not only the ever-increasing power density, but also the thermal challenges it brings.

Because liquids are many times better at storing and transferring heat than air, liquid cooling solutions can provide immediate and measurable benefits in computing efficiency, density, and performance. Using direct liquid cooling modules can increase computing performance and density, and reduce energy consumption.

Electronic component packages are subjected to a wide range of temperature differences. Due to differences in coefficients of thermal expansion ("CTE") of various packaged components, electronic component packages may warp as the temperature of the electronic component package changes.

The present disclosure provides a weight-optimized stiffener that provides warpage control for lidless packages while enabling direct liquid cooling of the chip and/or substrate. The stiffener may be constructed of a weight-optimized material, and its geometrical features may be further weight-optimized. Weight optimization of the stiffener reduces its thermal mass and weight concentration effects during attachment of the stiffener to the circuit assembly.

One aspect of the present disclosure provides a device including a weight-optimized stiffener having a top surface, a bottom surface, an irregularly shaped outer perimeter, and holes formed through the top and bottom surfaces , wherein the hole is adapted to receive a portion of the bottom surface of the substrate coupled to the stiffener by the adhesive. The reinforcement may be formed from silicon carbide particles in an aluminum matrix. According to some examples, the device may further include a substrate coupled to the bottom surface of the stiffener by an adhesive, a portion of the substrate protruding into the hole of the stiffener. For example, the bottom surface of the stiffener may have at least one recess for receiving at least one protrusion on the base plate. According to other examples, the bottom surface of the stiffener has a plurality of protrusions extending therefrom that are adjacent to the outer side surface of the substrate when the substrate is coupled to the bottom surface of the stiffener. The apparatus may further include a top plate coupled to the top surface of the stiffener and an O-ring for providing a seal between the stiffener and the top plate. In the case where the reinforcing member has a plurality of holes corresponding to the plurality of holes in the top plate, each hole of the plurality of holes in the reinforcing member may form a pair with a corresponding one of the plurality of holes in the top plate, the plurality of Each pair of the holes is adapted to receive a portion of the fastener therethrough for coupling the top panel to the stiffener. The top plate can have grooves in its inner surface that are configured to retain the O-rings when the top plate is coupled to the stiffener.

In some examples, the device may further include a manifold configured to be located within the enclosure formed by the base plate, the stiffener, and the top plate, the manifold configured to direct the cooled liquid to the base plate. For example, when the manifold is within an enclosure formed by the base plate, the stiffener, and the top plate, a portion of the manifold may be located within the bore of the stiffener and in direct contact with the base plate.

Another aspect of the present disclosure provides an assembly that includes a weight-optimized stiffener having a top surface, a bottom surface, an outer perimeter, and holes forming holes through the top and bottom surfaces an inner periphery; and a base plate coupled to the bottom surface of the stiffener by an adhesive, a portion of the base plate protruding into the hole of the stiffener. The reinforcement may be formed from silicon carbide particles in an aluminum matrix. The bottom surface of the stiffener may have at least one recess for receiving at least one protrusion on the base plate and a plurality of protrusions extending from the bottom surface adjacent the outer side surface of the base plate when the base plate is coupled to the bottom surface of the stiffener . In some examples, the assembly may further include a top plate coupled to the top surface of the stiffener and an O-ring for providing a seal between the stiffener and the top plate.

Yet another aspect of the present disclosure provides a method of assembling a semiconductor device for providing warpage control to a direct liquid cooling module. The method includes: providing a weight-optimized stiffener having a top surface, a bottom surface, an outer perimeter, and an inner perimeter forming a central hole through the top and bottom surfaces; providing a substrate having a top surface , the substrate includes circuitry on at least a first region of the top surface; and couples the top surface of the substrate to the bottom surface of the stiffener so that the first region of the top surface of the substrate is accessible through the holes of the stiffener.

1 is a perspective view of a packaging sub-assembly 100 for a semiconductor device including a substrate 120 bonded to a stiffener 140 using fasteners or threaded hardware 180 mounted to the stiffener.

The stiffener 140 has a top surface, a bottom surface, and holes through the top and bottom surfaces. The holes may be generally centered relative to the outer perimeter of the stiffener 140, but in other examples, the positions of the holes may be adjusted. For example, the size, shape, and location of the holes may be adapted based on the circuitry of the underlying substrate 120 to be exposed through the holes.

The substrate 120 may be coupled to the bottom surface of the stiffener, such as by adhesive or other bonding techniques. A portion of the stiffener 140 may cover a portion of the substrate 120 when the substrate is coupled to the bottom surface of the stiffener. For example, the substrate may include circuitry on at least a first region on its top surface. For example only, a circuit may include a microprocessor, memory, or other chips or components. When the base plate and the stiffener are assembled together, the first region of the base plate that includes the circuit is accessible through the holes of the stiffener. The portion of the substrate covered by the stiffener may, for example, not require accessible dead space or circuitry.

According to some examples described further below, the stiffener 140 and the base plate 120 may be included in an assembly with a top plate coupled to a top surface of the stiffener and an O-ring providing a seal between the stiffener and the top plate.

2A-2D illustrate an example method of assembly of the subassembly 100 . In Figure 2A, the stiffeners 140 are sintered together. As one example, the reinforcement may be formed from silicon carbide particles in an aluminum matrix. Finish post-processing such as finishing the perimeter of the reinforcement, sanding its top or bottom surface, or making sure the holes and holes are to specification. In FIG. 2B , the threaded hardware 180 is mounted to the top surface 142 of the stiffener 140 . In FIG. 2C , the substrate and/or wafer is bonded to the bottom surface or underside 144 of the stiffener 140 . In Figure 2D, the subassembly 100 is sputter coated prior to soldering the subassembly 100 to the main board. While FIGS. 2A-2D provide one example, it should be understood that variations may be made. For example, coupling techniques other than bonding may be used, different coating techniques may be used, and the like. For example, the reinforcements can be coated or plated with different metals or polymers to improve adhesion. In other examples, the stiffener can be made compatible with solder-based or polymer adhesive-based bonding.

FIG. 3A is a perspective view of the underside 144 of the stiffener 140 . The underside 144 of the stiffener 140 may have at least one groove for receiving at least one protrusion extending from the wafer and/or substrate. For example, the first and second grooves in the stiffener can be configured to receive respective first and second protrusions of the substrate.

According to one example, the protrusions extending from the lower side 144 may each be parallel to the edge of the central hole of the stiffener. When the substrate is coupled to the bottom surface of the stiffener, each protrusion of the plurality of protrusions may be adjacent to a respective outer side surface of the substrate. In one example, the stiffener may have four protrusions, wherein each protrusion is configured to be adjacent to a respective outer surface side of a rectangular wafer on the substrate when the substrate is coupled to the bottom surface of the stiffener. In other examples, additional protrusions or fewer protrusions may be included.

The stiffener 140 has an irregularly shaped outer perimeter or perimeter 146 . Aperture 150 defines an inner perimeter or perimeter 148 . The holes 150 extend through the top surface 142 and the bottom surface 144 of the stiffener 140 . The bottom surface 144 of the stiffener may include at least one groove 152 therein.

FIG. 3A shows the stiffener 140 having two recesses or grooves 152 adjacent the longer sides of the inner periphery 148 . A ramp surface 149 extending from the bottom surface 144 of the stiffener 140 toward the top surface 142 is also provided. Ramp surface 149 is adjacent to each of the shorter sides of inner perimeter 148 . Protrusions 156 extending outwardly from the bottom surface 144 of the stiffener 140 are also provided. Two protrusions 156 are shown forming a pair of protrusions 156 on each side of the stiffener 140 for a total of eight protrusions 156 extending outwardly from the bottom surface of the stiffener 140 . The stiffener 140 also includes a peripheral hole 160 extending through its top surface 142 and bottom surface 144 . As shown in FIG. 2A , the stiffener 140 includes eight peripheral holes 160 . This is only one example of the number of recesses or grooves 152 , protrusions 156 , and peripheral holes 160 that the reinforcement 140 may have. In other examples, the stiffener 140 may have more or less than two recesses or grooves 152 , more or less than two protrusions 156 , and more or less than eight peripheral holes 160 .

The irregularly shaped outer perimeter 146 of the stiffener 140 may provide for weight optimization. Instead of a rectangular outer perimeter, the stiffener 140 is designed with a perimeter curve 162 around each perimeter hole 160 . Each curve on the side surfaces of the stiffener may be about 180°, and each curve on the corners of the stiffener may be about 270°. The leads of the element 162 shown in FIG. 3A lead to the corners of the outer periphery 146 of the stiffener 140 , and the curves adjacent to the corners are on the aforementioned side surfaces of the stiffener 140 . The empty space between each adjacent curve 162 reduces the weight of the stiffener while still providing the structural area needed to control buckling.

The hardware 180 is installed through each of the peripheral holes 160 of the stiffener 140 . Each fastener or hardware 180 has a base 184 , a shaft 186 and a threaded hole 188 . To couple each piece of hardware 180 to the stiffener 140 , the shaft 186 is inserted from the bottom surface 144 , through the hole 188 and through the top surface 142 of the stiffener 140 until the base 184 is in direct contact with the bottom surface 144 . According to some examples, each fastener hole or hole in the stiffener corresponds to a respective hole or hole in the top plate. For example, each of the plurality of holes in the reinforcement member forms a pair with a respective one of the plurality of holes in the top plate. Each pair of the plurality of holes is adapted to receive a portion of the fastener therethrough for coupling the top plate to the stiffener.

Hardware 180 is available that can be attached to the microprocessor to enable it to handle pressure loads in direct liquid cooling, while still being light enough to be soldered onto a motherboard and handled in a high volume production environment. For example, the manifold can be configured to be located within the enclosure formed by the base plate, the stiffener, and the top plate. The manifold can be configured to supply cooled liquid to the substrate. When the manifold is within the enclosure formed by the base plate, the stiffener and the top plate, a portion of the manifold may be located within the central hole of the stiffener and in direct contact with the base plate.

As shown in FIGS. 3B and 4B , the substrate 120 is coupled to the bottom surface 144 of the stiffener 140 . The subassembly 100 includes a substrate 120, which also includes a die 130, which may also be referred to as a wafer. Die 130 may be an integrated circuit ("IC") chip, a system-on-chip ("SoC"), or a portion thereof, which may include various passive and active microelectronic devices such as resistors, capacitors, inductors, diodes Bulk, Metal Oxide Semiconductor Field Effect (“MOSFET”) Transistors, CMOS Transistors, Bipolar Junction Transistors (“BJT”), Laterally Diffused Metal Oxide Silicon (“LDMOS”) Transistors, High Power MOS Transistors Crystals, other types of transistors, or other types of devices. As an example, die 130 may include memory devices, logic devices, or other types of circuits. Die 130 is shown bonded to carrier substrate or substrate 120 . The substrate 120 may be, for example, a silicon substrate, a plastic substrate, a flexible substrate with layers such as polyimide and copper, a laminate substrate, a ceramic substrate, an interposer, or any other suitable support structure.

Substrate 120 includes top surface 122 , bottom surface 124 , and side surfaces 126 extending between top surface 122 and bottom surface 124 . Top surface 122 also includes an outwardly extending ramp surface 128 that forms the perimeter of wafer 130 . Adjacent to the longer side of the wafer 130 are protrusions 132 that also extend outward from the top surface 122 of the substrate 120 .

Before bonding the top surface 122 of the substrate 120 to the bottom surface 144 of the stiffener, a layer of adhesive 170 may be applied to the top surface of the substrate 120 and/or the bottom surface 144 of the stiffener 140 . As an example, FIG. 4A shows adhesive 170 applied to top surface 122 of substrate 120 . The adhesive is used to mechanically couple the substrate 120 and the stiffener 140 together. Any type of adhesive used in the industry can be used, including but not limited to natural adhesives, synthetic adhesives, drying adhesives, thermoplastic adhesives, reactive adhesives, pressure sensitive adhesives or any other commonly used adhesives.

When the base plate 120 is positioned relative to the stiffener 140 prior to joining these components, the protrusions 132 of the base plate are positioned within the grooves 152 of the stiffener 140 and the side surfaces 126 of the base plate 120 are positioned adjacent to the stiffener 140 The protrusions 132 are shown in FIGS. 3B and 4B . The ramp surface 128 of the base plate 120 is also positioned in contact with the corresponding ramp surface 149 of the stiffener 140 .

4B provides transparency of the substrate 120 bonded to the stiffener 140 showing the central hole 150 of the stiffener, even though at least the wafer 130 of the substrate 120 covers the central hole 150 when the substrate 120 is bonded to the stiffener 140 .

The subassembly 100 may be designed according to specific specifications. For example, the weight of the sub-assembly 100 should total less than 130 g so that the ball grid array ("BGA") is not crushed during solder reflow. In one example, the optimized weight of the stiffener 140 plus the hard body or rivet nut 180 is less than 50 g. Total package weight of sub-assembly 100 with wafer 130 on substrate 120 or printed circuit board (PCB) less than 25 g and the weight of the adhesive used to bond substrate 120 and wafer 130 to stiffener 140 is less than 5 g is about 80 g, which is well below the maximum weight specification of 130 g for the total package. In other examples, the stiffener 140 plus the hardware 180 can be greater than or less than 50 g, the wafer 130 on the substrate 120 can be greater or less than 25 g, and the adhesive used to bond the stiffener 140 to the substrate 120 can be greater than or less than 25 g less than 5 g.

When designing the components of subassembly 100, the total thermal mass should be low and the conductivity should be high so that heat can be applied from above to melt the underlying solder without damaging other components. The outer perimeter of the subassembly 100 can be designed to fit over existing pallets. The adhesive and O-ring joints/surfaces should provide a seal for the subassembly 100 against liquid water. The design of subassembly 100 should not promote any galvanic corrosion between electrolytically connected components. For the purpose of minimizing thermal stress, the thermal expansion of subassembly 100 should closely match the coefficient of the substrate to which it is bonded.

According to some examples, the reinforcement 140 may be made of AlSiC. The threaded hardware 180 may be attached after the AlSiC is fabricated. AlSiC is a cermet composite material consisting of silicon carbide particles (SiC) dispersed in an aluminum alloy matrix (A), as shown for example in FIG. 5 . The aluminum matrix contains a large number of dislocations and is responsible for the strength of the material. Dislocations can be introduced by SiC particles during cooling due to the different thermal expansion coefficients of dislocations.

AlSiC combines the benefits of the high thermal conductivity of metals (180 W/m K to 200 W/m K) and the low CTE of ceramics. Due to its composite characteristics, AlSiC is an advanced packaging material for high-tech thermal management. The thermal expansion of AlSiC can be tuned to match other materials such as silicon and gallium arsenide wafers and various ceramics. AlSiC helps remove waste heat when used in microelectronic devices as a substrate for power semiconductor devices and high-density multi-chip modules.

FIG. 6 is a thermal comparison diagram considering the specific material of the stiffener 140 made of AlSiC. As can be seen, the coefficient of thermal expansion of AlSiC is at least half that of, for example, planar circuit boards (in plane), 304 stainless steel, and copper. AlSiC has less than half the thermal conductivity of copper, but a much higher thermal conductivity than circuit boards or 304 stainless steel. The strain at +50°C and the relative strain in terms of percentage are also highlighted between these materials.

Figure 2A, discussed above, states that the stiffeners 140 are sintered together. AlSiC parts can also be fabricated by the near-net shape method by creating SiC preforms by metal injection molding of SiC-binder slurries, firing to remove the binder, and then infiltrating with molten aluminum under pressure. Parts can be manufactured with low enough tolerances that no further machining is required. According to other examples, further processing of the stiffener 140 may be performed to meet certain specifications.

AlSiC is completely dense, without voids, and hermetic. AlSiC can be plated with nickel and nickel gold or other metals by thermal spraying. Ceramic and metal inserts can be inserted into the preform prior to aluminum infiltration, resulting in a hermetic seal. AlSiC can also be prepared by mechanical alloying. When lower levels of SiC content are used, parts can be stamped from AlSiC sheets.

7A is an assembled view of the mating assembly 300, and FIG. 7B is an exploded view of the mating assembly 300 showing each of the components of the mating assembly. The mating assembly 300 includes the components of the subassembly 100 , namely the base plate 120 and wafer 130 , the stiffener 140 , the adhesive 170 and the hardware 180 , and the addition of the O-ring 190 , manifold 200 , top plate 220 and fasteners 280 part.

Each fastener hole or hole 160 in the stiffener 140 corresponds to a respective hole or hole 260 in the top plate 220 . For example, each of the plurality of holes 160 in the reinforcement member 140 forms a pair with a respective one of the plurality of holes 260 in the top plate 220 . As shown in FIG. 7B , each pair of the plurality of holes 260 is adapted to receive a portion of the fastener 280 therethrough for engaging the threaded hardware 180 and coupling the top plate 220 to the stiffener 140 .

The top plate 220 has a top portion 222 as shown in FIG. 7C and a bottom portion 224 which can be at least partially seen in the cross-sectional view of FIG. 7D . In FIG. 4A there is an arrow pointing to the top 222 that represents the flow conditions or channels that will extend through the top 222 and the bottom 224 , which are not shown with respect to the top plate 220 . A groove 230 is formed in the bottom 224 of the top plate 220 . The groove 230 is configured to retain the O-ring 190 when the top plate 220 is coupled to the stiffener 140 . In the exploded side view of the mating assembly 300 shown in FIG. 7C , and the corresponding cross-sectional view of FIG. 7D , the position of the O-ring 190 relative to the center hole 150 and its position on the reinforcement member 140 can be seen roughly oriented.

Figure 7D also shows an exploded view of the closure within which the manifold 200 is configured. As shown in FIG. 7A, when the base plate 120, the stiffener 140 and the top plate 220 are coupled together, a closure is formed. Manifold 200 is designed to direct flow over the microprocessor to significantly improve heat transfer between the microprocessor and the working fluid. A portion of the manifold 200 is designed to be located within the central hole 150 of the stiffener 140 and in direct contact with the wafer 130 of the substrate 120 when the manifold 200 is within the enclosure formed by the substrate 120, stiffener 140 and top plate 220. Manifold 200 sits on top of wafer 130 with flow channels. The manifolds are designed with complex cross flow paths for the coolant, resulting in improved cross flow paths between the wafers 130 and the working fluid. The cooled fluid or liquid flows through inlet channels 205 in manifold 200 and is directed onto wafer 130 . The liquid that has previously been used to cool the wafer 130 is drained through the outlet channel 215 .

When the mating assembly 300 is fully assembled as shown in FIG. 7A , the weight-optimized stiffener 140 may provide a seal on its top surface 142 by using an O-ring 190 and on its bottom surface by using an adhesive 170 Seals are provided on 144. The top plate has a groove in its inner surface that is configured to retain the O-ring when the top plate is coupled to the stiffener.

The stiffener 140 provides warpage control for the capless package while enabling direct liquid cooling of the wafer 130 and/or the substrate 120 . The reinforcement includes weight-optimized materials such as AlSiC and geometric features such as the irregularly shaped outer perimeter 146 . Weight optimization of the stiffener 140 reduces its thermal mass and weight concentration effects during attachment of the stiffener 140 to, for example, a mainboard.

Unless otherwise stated, the foregoing alternative examples are not mutually exclusive, but can be implemented in various combinations to achieve unique advantages. Because these and other variations and combinations of the above-discussed features may be utilized without departing from the subject matter defined by the scope of the claims, the foregoing description should be made by way of illustration of the subject matter defined by the scope of the claims, and not by the scope of the claims. in a way that restricts it. Furthermore, the provision of examples described herein and the phrases described with the words "such as", "including", etc. should not be construed as limiting patentable subject matter to particular examples; rather, such examples are intended to illustrate many One of the possible implementations. Furthermore, the same reference numbers in different figures may identify the same or similar elements.

100: Package sub-assembly 120: Substrate 122: Top surface 124: Bottom surface 126: Side Surface 128: Slope Surface 130: Die/Wafer 132: Protrusion 140: Reinforcement 142: Top surface 144: Bottom surface/underside 146: Irregularly shaped outer perimeter or perimeter 148: Inner perimeter or perimeter 149: Slope Surface 150: Center hole 152: Groove 156: Protrusion 160: Perimeter hole/hole 162: Peripheral Curves/Elements 170: Adhesive 180: Threaded hardware 184: Base 186: Shaft 188: Threaded holes 190: O-ring 200: Manifold 205: Entryway 215: Exit channel 220: top plate 222: top 224: Bottom 230: Groove 260: Hole 280: Fasteners 300: with the assembly

1 is a perspective view of a sub-assembly including a wafer bonded to a stiffener using threaded hardware mounted to the stiffener.

2A-2D illustrate an exemplary method of manufacturing the subassembly of FIG. 1 .

3A is a perspective view of the underside of the stiffener of FIG. 1 with installed hardware.

3B is a perspective view of the underside of the subassembly of FIG. 1 .

4A is a perspective view of an exemplary wafer.

4B is a perspective view of the wafer of FIG. 4A shown bonded to the underside of the stiffener.

5 is an enlarged photograph of an exemplary aluminum silicon carbide ("AlSiC") composite showing silicon carbide particles in an aluminum matrix.

Figure 6 is a thermal comparison chart considering specific materials for reinforcements made of AlSiC.

7A is an assembled view of a mating assembly including a top plate secured to the subassembly of FIG. 1 .

Figure 7B is an exploded perspective view of the mating assembly of Figure 7A.

Figure 7C is a side view of another exploded view of the mating assembly of Figure 7A.

7D is a cross-sectional view of the exploded side view of FIG. 7C taken along line A-A, which defines the midpoint of the shorter side surfaces of the top plate.

100: Package sub-assembly

120: Substrate

140: Reinforcement

180: Threaded hardware

Claims (20)

A device comprising: a weight-optimized stiffener having a top surface, a bottom surface, an irregularly shaped outer perimeter, and an inner perimeter forming an aperture through the top surface and the bottom surface, wherein the hole is adapted to receive a portion of the bottom surface of a substrate coupled to the stiffener by an adhesive. The device of claim 1, wherein the reinforcement is formed from silicon carbide particles in an aluminum matrix. The device of claim 1, further comprising: The base plate is coupled to the bottom surface of the reinforcement member by an adhesive, and a portion of the base plate protrudes into the hole of the reinforcement member. The device of claim 3, wherein the bottom surface of the stiffener has at least one recess for receiving at least one protrusion on the base plate. The device of claim 3, wherein the bottom surface of the stiffener has a plurality of protrusions extending therefrom, the plurality of protrusions being adjacent to the outer side surface of the substrate when the substrate is coupled to the bottom surface of the stiffener. The device of claim 3, further comprising: a top plate coupled to the top surface of the stiffener; and An O-ring for providing a seal between the stiffener and the top plate. The device of claim 6, wherein the reinforcement member has a plurality of holes corresponding to the plurality of holes in the top plate, and each hole of the plurality of holes in the reinforcement member is in contact with the plurality of holes in the top plate A respective one of the holes forms a pair, each pair of the plurality of holes is adapted to receive a portion of a fastener therethrough for coupling the top plate to the stiffener. The device of claim 6, further comprising: A manifold configured to be located within an enclosure formed by the base plate, the stiffener, and the top plate, the manifold configured to direct cooled liquid to the base plate. 8. The apparatus of claim 8, wherein when the manifold is within the enclosure formed by the base plate, the stiffener and the top plate, a portion of the manifold is located within the hole of the stiffener and is in direct contact with the base plate . 6. The device of claim 6, wherein the top plate has a groove in an inner surface thereof, the groove configured to retain the O-ring when the top plate is coupled to the stiffener. An assembly containing: a weight-optimized stiffener having a top surface, a bottom surface, an outer perimeter, and an inner perimeter forming an aperture through the top surface and the bottom surface; and a base plate coupled to the bottom surface of the reinforcement member by an adhesive, a portion of the base plate protruding into the hole of the reinforcement member. The assembly of claim 11, wherein the reinforcement is formed of silicon carbide particles in an aluminum matrix. The assembly of claim 11, wherein the bottom surface of the stiffener has at least one recess for receiving at least one protrusion on the base plate. The assembly of claim 11, wherein the bottom surface of the reinforcement member has a plurality of protrusions extending therefrom, the plurality of protrusions being adjacent to the outer side surface of the base plate when the base plate is coupled to the bottom surface of the reinforcement member . As in the assembly of claim 12, further comprising: a top plate coupled to the top surface of the stiffener; and An O-ring for providing a seal between the stiffener and the top plate. The assembly of claim 15, wherein the reinforcement member has a plurality of holes corresponding to the plurality of holes in the top plate, each hole of the plurality of holes in the reinforcement member and the plurality of holes in the top plate A respective one of the holes forms a pair, and each pair of the plurality of holes is adapted to receive a portion of a fastener therethrough for coupling the top plate to the stiffener. As in the assembly of claim 15, further comprising: A manifold configured to be located within an enclosure formed by the base plate, the stiffener, and the top plate, the manifold configured to direct cooled liquid to the base plate. The assembly of claim 17, wherein when the manifold is within the enclosure formed by the base plate, the stiffener, and the top plate, a portion of the manifold is located within the hole of the stiffener, and the manifold A bottom surface of the substrate is in direct contact with the substrate. The assembly of claim 15, wherein the top plate has a groove in an inner surface thereof, the groove configured to retain the O-ring when the top plate is coupled to the stiffener. A method of assembling a semiconductor device for providing warpage control to a direct liquid cooling module, the method comprising: providing a weight-optimized stiffener having a top surface, a bottom surface, an outer perimeter, and an inner perimeter forming a central hole through the top and bottom surfaces; providing a substrate having a top surface, the substrate including circuitry on at least a first region of the top surface; and The top surface of the substrate is coupled to the bottom surface of the stiffener so that the first region of the top surface of the substrate can be accessed through the hole of the stiffener.

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